Question

how is friction caused?.

Answer 1

The rougher the surfaces the more often “hills” will have to push over each other, and the steeper those hills will be. For most practical purposes friction is caused by the physical roughness of the surfaces involved. However, even if you make a surface perfectly smooth there's still some friction.

Answer 2

hiii....

here is ur answer....

Causes of Friction. Friction is a force that resists the relative motion between two objects or materials. The causes of this resistive force are molecular adhesion, surface roughness, and deformations. Adhesion is the molecular force resulting when two materials are brought into close contact with each other.

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